Jarosław Wojtuń, Bartosz Czaja, Tomasz Grasza, Rafał Przesmycki, Jan M. Kelner, Cezary Ziółkowski, Radek Zavorka, Josef Vychodil 等 12 位作者
This paper investigates the influence of reference waveform selection on temporal dispersion estimation in a time-varying radio channel at 38 GHz. Three reference waveforms-numerically generated in MATLAB, measured through a conducted connection, and recorded in an anechoic chamber -are compared using the same wideband channel measurements conducted in a dynamic road environment. Their effects on the estimated power delay profiles (PDPs), mean delay, and root mean square (RMS) delay spread are evaluated. Despite noticeable differences in the time-domain and spectral characteristics of the reference waveforms, the resulting PDPs exhibit similar multipath structures, while the estimated temporal dispersion parameters show relatively small differences. The results indicate limited sensitivity to reference waveform selection under the investigated measurement conditions.
Jarosław Wojtuń, Bartosz Czaja, Tomasz Grasza, Jan M. Kelner, Cezary Ziółkowski, Radek Zavorka, Josef Vychodil, Tomas Mikulasek 等 11 位作者
Root mean square (RMS) delay spread is a key parameter characterizing temporal dispersion in radio propagation channels. Its estimation from measured power delay profiles (PDPs), however, depends strongly on the adopted power threshold. This paper investigates the sensitivity of RMS delay spread estimates to relative PDP thresholding in a time-varying millimeter-wave channel at 33 GHz. The analysis uses wideband channel sounding measurements conducted in a dynamic road environment with moving vehicles. The temporal evolution and empirical cumulative distributions of RMS delay spread are evaluated for thresholds ranging from -20 to -50 dB. Reducing the threshold increases the median RMS delay spread from approximately 140 to 168 ns and the 90th percentile from 200 to 210 ns. Both statistics converge at lower thresholds, with -40 dB providing a practical convergence level. The results emphasize the importance of threshold selection for reliable channel characterization and consistent comparison of measurements.